From patchwork Tue Nov 9 03:04:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rao, Lei" X-Patchwork-Id: 12609641 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48011C433EF for ; Tue, 9 Nov 2021 03:16:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E6B7061167 for ; Tue, 9 Nov 2021 03:16:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E6B7061167 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:39546 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mkHca-0000hi-4w for qemu-devel@archiver.kernel.org; Mon, 08 Nov 2021 22:16:28 -0500 Received: from eggs.gnu.org ([209.51.188.92]:49804) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mkHZm-0005eL-4z for qemu-devel@nongnu.org; Mon, 08 Nov 2021 22:13:34 -0500 Received: from mga07.intel.com ([134.134.136.100]:45865) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mkHZk-0005IH-DG for qemu-devel@nongnu.org; Mon, 08 Nov 2021 22:13:33 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10162"; a="295808371" X-IronPort-AV: E=Sophos;i="5.87,219,1631602800"; d="scan'208";a="295808371" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Nov 2021 19:13:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,219,1631602800"; d="scan'208";a="491490340" Received: from unknown (HELO localhost.localdomain.bj.intel.com) ([10.238.156.105]) by orsmga007.jf.intel.com with ESMTP; 08 Nov 2021 19:13:26 -0800 From: "Rao, Lei" To: chen.zhang@intel.com, zhang.zhanghailiang@huawei.com, quintela@redhat.com, lukasstraub2@web.de, dgilbert@redhat.com Subject: [PATCH v7 2/2] Reduce the PVM stop time during Checkpoint Date: Tue, 9 Nov 2021 11:04:55 +0800 Message-Id: <1636427095-11739-3-git-send-email-lei.rao@intel.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1636427095-11739-1-git-send-email-lei.rao@intel.com> References: <1636427095-11739-1-git-send-email-lei.rao@intel.com> Received-SPF: pass client-ip=134.134.136.100; envelope-from=lei.rao@intel.com; helo=mga07.intel.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Rao, Lei" , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Rao, Lei" When flushing memory from ram cache to ram during every checkpoint on secondary VM, we can copy continuous chunks of memory instead of 4096 bytes per time to reduce the time of VM stop during checkpoint. Signed-off-by: Lei Rao Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Lukas Straub Tested-by: Lukas Straub Reviewed-by: Juan Quintela --- migration/ram.c | 48 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 45 insertions(+), 3 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index d5f98e6..863035d 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -845,6 +845,41 @@ migration_clear_memory_region_dirty_bitmap_range(RAMBlock *rb, } } +/* + * colo_bitmap_find_diry:find contiguous dirty pages from start + * + * Returns the page offset within memory region of the start of the contiguout + * dirty page + * + * @rs: current RAM state + * @rb: RAMBlock where to search for dirty pages + * @start: page where we start the search + * @num: the number of contiguous dirty pages + */ +static inline +unsigned long colo_bitmap_find_dirty(RAMState *rs, RAMBlock *rb, + unsigned long start, unsigned long *num) +{ + unsigned long size = rb->used_length >> TARGET_PAGE_BITS; + unsigned long *bitmap = rb->bmap; + unsigned long first, next; + + *num = 0; + + if (ramblock_is_ignored(rb)) { + return size; + } + + first = find_next_bit(bitmap, size, start); + if (first >= size) { + return first; + } + next = find_next_zero_bit(bitmap, size, first + 1); + assert(next >= first); + *num = next - first; + return first; +} + static inline bool migration_bitmap_clear_dirty(RAMState *rs, RAMBlock *rb, unsigned long page) @@ -3895,19 +3930,26 @@ void colo_flush_ram_cache(void) block = QLIST_FIRST_RCU(&ram_list.blocks); while (block) { - offset = migration_bitmap_find_dirty(ram_state, block, offset); + unsigned long num = 0; + offset = colo_bitmap_find_dirty(ram_state, block, offset, &num); if (!offset_in_ramblock(block, ((ram_addr_t)offset) << TARGET_PAGE_BITS)) { offset = 0; + num = 0; block = QLIST_NEXT_RCU(block, next); } else { - migration_bitmap_clear_dirty(ram_state, block, offset); + unsigned long i = 0; + + for (i = 0; i < num; i++) { + migration_bitmap_clear_dirty(ram_state, block, offset + i); + } dst_host = block->host + (((ram_addr_t)offset) << TARGET_PAGE_BITS); src_host = block->colo_cache + (((ram_addr_t)offset) << TARGET_PAGE_BITS); - memcpy(dst_host, src_host, TARGET_PAGE_SIZE); + memcpy(dst_host, src_host, TARGET_PAGE_SIZE * num); + offset += num; } } }